1. Field of the Invention
The present invention relates to an apparatus and method for producing trichlorosilane in which metal silicon powder is reacted with hydrogen chloride gas while being fluidized by the hydrogen chloride gas, thereby producing trichlorosilane.
2. Description of Related Art
Trichlorosilane (SiHCl3) used as a raw material for producing high purity silicon is produced by reacting metal silicon powder (Si) of about 98% in purity with hydrogen chloride gas (HCl).
The apparatus for producing trichlorosilane is, for example as disclosed in Japanese Published Unexamined Patent Application, First Publication No. H08-59221, provided with a reactor, a raw material supply device for supplying metal silicon powder to the bottom of the reactor, and gas introduction device for introducing hydrogen chloride gas with which metal silicon powder is reacted. In the apparatus for producing trichlorosilane, the metal silicon powder inside the reactor is reacted with hydrogen chloride gas while being fluidized with the hydrogen chloride gas, thereby taking out the generated trichlorosilane from the upper part of the reactor. A heat transfer tube which flows a heating medium along the vertical direction is provided inside the reactor.
Incidentally, metal silicon powder is fluidized at the inner bottom of the reactor by ascending hydrogen chloride gas which is introduced from therebelow, and the metal silicon powder is contacted with the hydrogen chloride gas to cause a reaction during fluidization. In this embodiment, the hydrogen chloride gas ascends like bubbles from the lower part to the upper part in the fluidized bed of the metal silicon powder. However, in the meantime, the bubbles grow greater at the upper part of the reactor than at the lower part thereof. When the bubbles of hydrogen chloride gas grow greater, there is a decrease in the contact area with the metal silicon powder, resulting in a tendency of lower efficiency of the reaction takes place particularly at the upper part of the reactor.
The present invention has been made in view of the above situation, an object of which is to provide an apparatus and method for producing trichlorosilane in which hydrogen chloride gas introduced from the lower part of the reactor is made an effective contribution even at the upper part of the reactor, thereby attaining a higher reaction efficiency.